A house was washed down the North Fork of the Toutle River after Mount St. Helens erupted on May 18, 1980. A huge mud flow caused a number of houses to be carried away and wash up on the banks of the river. (Photo by Grant Haller) less

A house was washed down the North Fork of the Toutle River after Mount St. Helens erupted on May 18, 1980. A huge mud flow caused a number of houses to be carried away and wash up on the banks of the river. ... more

Photo: P-I File

A house was washed down the North Fork of the Toutle River after... Photo-801461.6600 - seattlepi.com

Image 34 of 44

Looking inside the crater of Mount Saint Helens on Wednesday May 17, 2006.

Looking inside the crater of Mount Saint Helens on Wednesday May 17, 2006.

People begin to clear W. Broadway in Ritzville of ash from Mount St. Helens. This picture was made just after the eruption on May 18, 1980 (Photo by Terry Janzen)

People begin to clear W. Broadway in Ritzville of ash from Mount St. Helens. This picture was made just after the eruption on May 18, 1980 (Photo by Terry Janzen)

Photo: P-I File

People begin to clear W. Broadway in Ritzville of ash from Mount... Photo-801465.6600 - seattlepi.com

Image 38 of 44

A view from the rim of Mount St. Helens.

A view from the rim of Mount St. Helens.

Photo: P-I File

A view from the rim of Mount St. Helens. Photo-801468.6600 - seattlepi.com

Image 39 of 44

A view of Mt. St. Helens from Johnston Ridge on Tuesday, April 19, 2005 at Mt. St. Helens National Volcanic Monument. (Joshua Trujillo, Seattle Post-Intelligencer)

A view of Mt. St. Helens from Johnston Ridge on Tuesday, April 19, 2005 at Mt. St. Helens National Volcanic Monument. (Joshua Trujillo, Seattle Post-Intelligencer)

Photo: P-I File

A view of Mt. St. Helens from Johnston Ridge on Tuesday, April 19,... Photo-814775.6600 - seattlepi.com

Image 40 of 44

Taboola Gallery Frame Item-85307.6600 - seattlepi.com

Image 41 of 44

Mount St. Helens in a panoramic shot before the eruption.

Mount St. Helens in a panoramic shot before the eruption.

Photo: P-I File

Mount St. Helens in a panoramic shot before the eruption. Photo-814778.6600 - seattlepi.com

Image 42 of 44

Mount St. Helens after the eruption from the same vantage point.

Mount St. Helens after the eruption from the same vantage point.

Photo: P-I File

Mount St. Helens after the eruption from the same vantage point. Photo-814780.6600 - seattlepi.com

Image 43 of 44

In this photo provided by the USGS, a helicopter flies past a new "slab" rock growth in the crater of Mount St. Helens, Friday, April 28, 2006. (AP Photo/USGS Cascades Volcano Observatory, Dan Dzurisin)

In this photo provided by the USGS, a helicopter flies past a new "slab" rock growth in the crater of Mount St. Helens, Friday, April 28, 2006. (AP Photo/USGS Cascades Volcano Observatory, Dan Dzurisin)

Photo: P-I File

In this photo provided by the USGS, a helicopter flies past a new... Photo-801410.6600 - seattlepi.com